integrate updated DCPU implementation with Entitas

[icarroll]

[icarroll]

• each DCPU and peripheral entity will have an interrupt queue component
• any peripheral with an interrupt in its queue will be run by that peripheral's system at the next tick
• peripheral entities that need to do additional processing or counting elapsed time will have an arrangement with their systems such as a GO flag component
• DCPU entity will have a GO flag component that can be used by peripherals (such as the disk drive) to stop the DCPU from executing until the requested blocking operation is complete
• in general, peripherals will service interrupts in their queue regardless of whether they have a GO flag
• my (Octa9on/icarroll) reading of the spec is that while a long hardware interrupt is being executed (blocking disk read for example), no other interrupts are serviced
  • this could cause problems with running background processes (like making sure the ship flies straight), so perhaps we should implement different behavior